I got 9 drives and all of them have the same issue. Reads are normal in the 185-205 MB/s range but writes always start high then afte 3-4 seconds they go down to 70MB/s.
Replaced sata cables
Used internal sata ports on motherboard (supermicro)
used another motherboard (asus)
Used storage spaces and speeds are even worse in the 20-25 MB/s range.
I have 3 brand new 6tb ultrastar he8 and these get 180-190 MB writes/s on the same two motherboard.
Did I get 9 faulty drives or maybe I’m missing something obvious?